On my RCA truflat TV, a good section of the picture is cut off on each side because the picture is too big. Can anyone tell me how to correct this. It's running of a StarChoice receiver in case it matters.

Your on the wrong forum,
this topic is ment to be at the Computer Help.
This is a discussion forum
Soon maybe Agent F move it there.

This is the right forum, this is not a computer help topic. Also, Agent F isn't the only one who can move topics.

Anyway, onto the topic, do you have a widescreen or square size screen?

On the remote you got with your tv, there should be a button that says zoom or a menu button that you can find something to do with zoom. Just unzoom a bit.